1. Field of the Invention
The present invention is related to a communication device, and more particularly to a communication device having an internal antenna system.
2. Description of the Related Art
Communication devices, such as radiotelephones, are being driven by the marketplace towards smaller and smaller sizes. Consumer and user demand has continued to push a dramatic reduction in the size of such communication devices. Consumers further are very interested in smaller phones with concealed (internal) antennas that are not susceptible to damage by catching on clothing or other objects. The reduction in size and desirability of an internal antenna provides additional challenges to the device designers to achieve adequate antenna electrical performance.
With the increased use of wireless communication devices, available spectrum to carry communication signals is becoming limited. In many cases, network operators are providing services on multiple frequency bands to accommodate its customers. For example, network operators providing service on the Global System of Mobile (GSM) communication system in an 850 MHz (Mega Hertz) or a 900 MHz frequency band may also provide service on the Digital Communication System (DCS) at an 1800 MHz frequency band or a Personal Communication System (PCS) at a 1900 MHz frequency band. Network operators are further offering other services such as access to Global Positioning Systems (GPS) that operates at 1.575 GHz, Bluetooth operation at 2.4 GHz, and Universal Mobile Telecommunications Service (UMTS) that uses the spectrum from 1.92 GHz to 1.98 GHz for transmission and 2.11 GHz to 2.17 GHz for reception. Further, to meet the demand for the various services, device manufacturers are designing similar communication devices for multiple frequency bands and communication protocols. Accordingly, it is desirable for communication devices, such as cellular radiotelephones, to be able to communicate at multiple frequencies using multiple communication protocols within a compact size.